The present application claims the priority of JP 2000-399442 filed in Japan on Dec. 27, 2000, the entire contents of which are hereby incorporated herein by reference.
1. Field of the Invention
The invention of the present application relates to a substrate processing device suitable for use in the manufacture of display devices such as liquid crystal displays.
2. Discussion of Related Art
In the manufacture of various display devices, such as liquid crystal displays and plasma displays, a process such as surface-processing must be administered on a plate-shaped material that forms the base of the device (hereinbelow referred to as the substrate). By way of example, in liquid crystal displays, a process to form a transparent electrode on the plate surface (surface that is not the peripheral surface) of the glass substrate is required.
The substrate processing device employed in the processing of this kindxe2x80x94because the processing of the substrate is performed in a predetermined atmospherexe2x80x94comprises a chamber configured in such a way that it can be pumped out to a vacuum or a predetermined gas can be introduced to the inner space. As different processes are continuously performed therein and the pressure must be gradually lowered from atmospheric pressure, the configuration that is adopted comprises a plurality of chambers.
Substrate processing devices of the prior art such as this may, in terms of the layout of the chambers, be broadly divided into two types. One is known as the inline-type and the other is known as the cluster tool-type.
FIG. 9 shows the schematic configuration of a conventional inline-type substrate processing device. The inline-type device is a configuration in which a plurality of chambers 11, 2, 3 and 12 are longitudinally-provided in a straight line. A carry system, which carries the substrate 9, is provided in such a way that as to penetrate the plurality of chambers 11, 2, 3 and 12. In addition, gate valves 10 are provided between the chambers 11, 2, 3 and 12.
The substrate 9 is carried in sequence through the chambers by the carry system in a state in which it is mounted on a tray 91, wherein the processing is performed. One of these plurality of chambers is a load-lock chamber 11 which opens to the atmosphere when the substrate 9 is carried in, and the other is a load-lock chamber 12 which opens to the atmosphere when the substrate 9 is carried out. Several of the remaining chambers are chambers for processing (hereinbelow, processing chambers) 2. In addition, a chamber 3, provided between the processing chamber 2 and the load-lock chamber 11 or unload-lock chamber 12, constitutes a pressure-adjustment chamber. As there is a large pressure difference between the load-lock chamber 11 (or unload-lock chamber 12) and the processing chamber 2, the pressure adjustment chamber 3 maintains and adjusts the atmosphere to an interim pressure there-between.
As shown in FIG. 9, the configuration of the carry system enables the movement of the tray 91, on which the substrate 9 is mounted, by the use of carry rollers 41. These carry rollers 41 constitute a pair of small disk-shaped members provided at both ends of a rotating shaft extending perpendicular with the direction of carry-in the horizontal direction. The carry system is configured by the provision of, in a predetermined interval in the direction of carry, a large number of groups of rotating shafts and pairs of carry rollers 41. As is clear from FIG. 9, the substrate 9 is carried and processed horizontally.
On the other hand, FIG. 10 shows, as another example of a conventional substrate processing device, a schematic configuration of a cluster tool-type device. The cluster tool-type device is a configuration in which, in the perimeter of a transfer chamber 5 in which a transfer robot 42 is provided in the inner part, load-lock chambers 11 and plurality of processing chambers 2 are provided. In the example shown in FIG. 10, two load-lock chambers 11 are provided. In addition, gate valves 10 are provided between the transfer chamber 5, load-lock chambers 11 and processing chambers 2.
The transfer robot 42 takes out the substrate 9 from one load-lock chamber 11 and transfers it in sequence to the processing chambers. The transfer robot 42, following processing, returns the substrate 9 to the other load-lock chamber 11. It will be noted that, although the load-lock chamber 11 shown in FIG. 10 also comprises the function of the unlock load chamber 12 in the device shown in FIG. 9, the name load-lock chamber is used without alteration.
The transfer robot 42 is a multi-jointed type robot. The substrate is mounted and carried on the tip-end of the arm thereof. To transfer the substrate to a predetermined position the transfer robot 42 performs arm extension and contraction, rotation, and a range of vertical movements. The substrate is mounted and transferred on the arm horizontally. In addition, the substrate is also supported and processed horizontally within the processing chamber 2.
A marked trend of increase in size of the substrates in substrate processing devices of this kind is occurring. By way of example, a full-scale extension of liquid crystal display and plasma display technology to not only the display parts of computers but also wall-hanging type televisions is thought to be just around the corner, and the display area of wall-hanging type televisions is large by comparison to the display area of computers. For this reason, the substrates thereof are also larger. In addition, as a general trend, instances where two or more products are manufactured from one substrate to increase productivity and reduce manufacturing costs has increased and, accompanying this, the substrates have increased in size.
As a result of this increase in size of the substrates, the above-described substrate processing devices of the prior art harbor the following problems, or, it is predicted they will harbor them in the future.
First, in inline-type and cluster tool-type devices of the prior art, the substrate is maintained horizontal during carry and processing. Accordingly, when the substrate size is increased, the occupied space in the horizontal direction of the chambers (hereinbelow referred to simply as occupied area) will increase as a matter of course. As a result, the occupied area of the device increases as a whole.
In addition, in the device of an inline-type device shown in FIG. 9, when the chambers 11, 2, 3 and 12 are increased in size, the length in the line direction is increased. At the present time, in the manufacture of televisions for the home such as wall-hanging type televisions, the processing of a substrate of a size of the order of 1 mxc3x971.2 m is required and, when a device for processing a substrate of this magnitude is configured using an inline-type device, the length in the line direction reaches 10 or more meters.
In addition, in the cluster tool-type device shown in FIG. 10, a size increase of the substrate is linked to an increase in the occupied area of the chambers and leads to an increase in the occupied area of the device as a whole. The most serious problem affecting cluster tool-type devices is a size increase of a transfer chamber 5.
As is clear from the transfer chamber 5 of FIG. 10, even though the center axis for rotational movement of a transfer robot 42 is set in the center of the transfer chamber 5, because the substrate is mounted on the end of the arm thereof, the substrate rotates about the rotating axis in a position eccentric from the center of the transfer chamber 5. Accordingly, the average space required for rotation of the substrate in the horizontal direction (hereinbelow required rotation radius) is twice or more the length of the short side or long side of the substrate. For this reason, there is a doubling of the required rotation radius when the substrate is increased in size, and the transfer chamber 5 is further increased in size. By way of example, where a substrate of the above-described 1 mxc3x971.2 m size is processed, the required rotation radius exceeds 2 m.
Although it is generally necessary for the transfer chamber 5 to be pumped out to a vacuum using a vacuum pumping system, there are problems in that, when the transfer chamber 5 is increased in size, a long time is required to perform pumping to a predetermined vacuum, and the scale of the configuration of the pump system is greater which leads to higher costs. In addition, a transfer chamber 5 such as this is essentially not used in the actual processing of the substrate. The occupation of a majority of the occupied area of the equipment by this component is undesirable in terms of equipment design.
A separate problem resulting from this increase in size of substrates is warp of the substrate during transfer. In display devices such as liquid crystal displays, there is a strong market demand for both an increase in surface display area and for thin films. For this reason, the substrates, while they have increased in size, are not very thick. On the contrary, the trend is for them to be thinner. Citing the above-described example of a size of the order of 1 mxc3x971.2 m, the thickness thereof is of the order of 0.7 mm. Several years ago this was of the order of 0.9 mm.
When the substrate 9 of a size and thinness of this order is carried horizontally and processed, there is a problem of warp of the substrate due to its own weight. By way of example, although, as described, carry is performed by the movement of a tray 91 by carry rollers 41 in an inline-type device, the substrate 9 is liable to sag downward and warp due to the warp of the tray 91 that occurs at sections that are not in contact with the carry rollers 41. In addition, in cluster tool-type equipment as well, the substrate 9 sags downward and warps at sections on both sides that are not in contact with the arm.
When processing is performed in a state in which warp such as this has been generated, the processing is not uniform and there is a fear of imparting damage, such as display blotches, to the performance of the product. In addition, as a result of the non-uniform residual inner stresses on the substrate, there is a fear that damage such as cracks in the substrate will be liable to occur, and of a reduction in reliability of the product.
In addition, in the cluster tool-type devices, the transfer of the increased size substrate using the transfer robot 42 is, in reality, very difficult. That is to say, for the holding of a large substrate, the arm must be of a sufficient size and rigidity. In addition, there is a need to be able to expand and contract, rotate, and move the larger scale arm up and down with high precision, and the production of a movement mechanism such as this, having adequate precision, is very difficult. Accordingly, it is felt that transfer using an articulated robot will have reached its limitations in the not-too-distant future.
A further problem as a result of an increase in size of the substrates is the problem of maintenance.
That is to say, the chambers from which the equipment is configured are, for reasons of maintenance, manufactured so that the inner part can be opened. By way of example, where a transfer error arises within the chamber due to some condition, the operation of the equipment is stopped and the inner part of the chamber is checked. By way of example, where it is discovered that the substrate 9 is not mounted correctly on carry rollers 41 or is not mounted correctly on the arm, the operation of the equipment is restarted after the substrate has been restored to the correct position.
The chambers, for the purpose of maintenance, are provided with an opening/closing door. Normally, the upper plate part of the chamber is fixed by way of a hinge to form the opening/closing door. The reason the upper plate part is used as the opening/closing door is because, by the opening of the opening/closing door, a check of the plate surface of the substrate that constitutes the processing target can be made. The opening/closing door is opened and a check is made with the naked eye as to whether there are any foreign objects or the like on the plate surface of the substrate.
However, when the substrate is increased in size, which leads to an increase in the size of the chambers, the opening/closing door is also increased in size. When the substrate is increased to a size of the order described above, the opening closing door also reaches a size that exceeds a 1 m edge. When the opening/closing door increases in size to this extent, opening and closing is difficult using just the strength of the operator and a large-scale mechanism such as a crane is required.
The application of the present invention, which is designed in order to resolve the above-described problemsxe2x80x94resulting from the increase in size of the substrate, has marked technological significance which includes the suppression of increase of occupied area, the resolution of the problem of warp of the substrate, and easier maintenance.
According to one embodiment of the invention a substrate processing device comprises a plurality of vacuum process chambers, each of which administers a prescribed process to a substrate therein; a through-chamber which constitutes a vacuum chamber, the plurality of vacuum process chambers are hermetically-connected to a perimeter of the through-chamber; a carry system which carries a substrate in sequence, via the through-chamber, to the plurality of vacuum process chambers, the carry system comprises a substrate holder which holds the substrate upright in such a way that a plate surface thereof forms an angle to the horizontal of between 45xc2x0 and 90xc2x0; and a horizontal movement mechanism which moves the substrate holder via the through-chamber to the plurality of vacuum process chambers.
According to another embodiment of the invention, a substrate processing device, comprises a plurality of through-chambers, each of which includes a hermetically-connected vacuum chamber; a plurality of processing chambers that are hermetically-connected to the plurality of through-chambers; a carry system that carries a substrate in sequence to the processing chambers, the carry system comprises a substrate holder which holds the substrate upright in such a way that a plate surface thereof forms an angle to the horizontal of between 45xc2x0 and 90xc2x0; and a horizontal movement mechanism which moves the substrate holder to each of the processing chambers via at least a plurality of the through-chambers.
According to yet another embodiment of the invention, a through-chamber has a perimeter to which a plurality of vacuum processing chambers are hermetically-connected. The through chamber comprises a vacuum chamber; a horizontal movement mechanism including a substrate holder for holding a substrate, the horizontal movement mechanism horizontally moves the substrate holder through the vacuum chamber, and the substrate holder holds the abovementioned substrate upright in such a way that the plate surface thereof forms a holding angle to the horizontal of between 45xc2x0 and 90xc2x0, and a direction altering mechanism which alters the direction of movement of the substrate holder by rotating the substrate holder and horizontal movement mechanism about a vertical rotating axis.